{{trigger.Subject}} does not seem to work dynamically

Trying this token for the first time and I'm trying to collect an interesting moment in an alert email, for a clicked link, on a dynamic email.

Everything else seems to be working correctly except this token {{trigger.Subject}}. It seems it is only populating the default subject line and not the subject line the person actually got when it was dynamically populated. I double checked the email and it in fact has a different subject line from the default and I know the email version they got was correct because of the links they are clicking on.

Does not work with dynamic subjects? Am I using it wrong?

Any help is appreciated.

Thanks!